I. Field of the Invention
This invention relates generally to vessel occluding devices used during surgical procedures and more specifically to the design of a vessel occluder having an improved clamping structure for maintaining constant pressure on the blood vessel being constricted.
II. Description of the Prior Art
Many different types of vessel occluders are well known in the art. In general, they include a flexible rubber tubular sheath having a separate retractor which can be passed completely through the sheath. The retractor normally has a hook at its distal end and a handle at its proximal end. A flexible tape or cord is looped around the blood vessel to be constricted and the ends of the cord are snared in the hook of the retractor. When the retractor is withdrawn from the proximal end of the flexible sheath, the ends of the cord are also drawn through the sheath. The loop around the blood vessel may then be drawn tight such that the vessel is compressed and occluded against the distal end of the sheath.
Prior art vessel occluders also employ a suitable clamping arrangement for maintaining the cord taut. Typical prior art clamping structures are disclosed in the Wolvek U.S. Pat. No. 3,786,816 and the Ferguson et al U.S. Pat. No. 3,877,434. In the Wolvek arrangement, the flexible sheath is provided with an outwardly projecting pedestal on which the base of a generally U-shaped metal spring element rests. A notch is provided in the base which is adapted to cooperate with one of the legs of the U-shaped spring. When this leg is inserted into the notch, the side walls of the flexible sheath are compressed against the tape or cord to prevent axial movement thereof.
In the Ferguson arrangement a simple plug is used at the proximal end of the sheath to maintain the desired tension in the vessel occluding cord. A significant drawback to the Ferguson et al approach is the fact that it is generally a two-handed operation to effect a release of the cord so that blood can be made to flow through the previously constricted vessel. That is, one hand must be used to hold the sheath while the other hand is used to remove the plug.
The present invention is considered to be a significant improvement over the structure disclosed in the aforementioned prior art patents. Specifically, vessel occluders made in accordance with the teachings of the present invention offer the advantage of low cost manufacture and ease of use during surgical procedures. The clamping arrangement of the present invention may be released with only one hand and, accordingly, the surgeon has his other hand free to perform simultaneous manipulations.